The purpose of the tissue core is to facilitate research on lymphoid malignancies by members of the City of Hope Lymphoma Spore. The core provides services in the following areas; (1) acquisition and banking of fresh and paraffin-fixed tissues of lymphoma patients at City of Hope, including specimens obtained prospectively and retrospectively; (2) comprehensive work-up of lymphoma specimens to ensure correct diagnosis, classification, and detection of minimal residual disease, including immunohistochemical, flow cytometric, molecular pathologic, and cytogenetic studies; (3) performance and assistance in routine histologic processing and immunohistochemical staining of lymphoma tissues, including animal tissue, and preparations from cell lines, as well as specialized histologic services such as preparation of multitumor blocks or tissue microarrays to the specifications of researchers; (4) performance and assistance in Laser Capture microdissections from paraffin or frozen sections to obtain enrichment of specific cell types including isolation of malignant cells for analysis of proteins, RNA and/or DNA content; (5) flow cytometry studies, including complex characterization of lymphoma and host cell populations; (6) cytogenetic studies, including identification of vector-carrying cells and (7) consultation services to other SPORE investigators. In addition a Hematopoietic cell tissue bank has been established to prospectively collect and store fresh bone marrow, peripheral blood and peripheral blood stem cell samples from lymphoma patients undergoing autologous peripheral stem cell transplant (aPBSCT). This bank will support studies in Project 2 evaluating pathogenesis and predictors for t-MDS/AML in lymphoma patients post-aHCT. Samples are obtained pre-transplant and post-transplant at 100 days, 6 months, 1 year, and then annually through 5 years after transplant. Aliquots of the PBSC autograft are also banked. The core also collects and enters follow up outcome information for all patients. The core uses an IRB approved protocol for sample and data collection (see Appendix). The core also follows patients who have received their initial transplant treatment but who are not under current followup at City of Hope, by contacting the treating physician, and if necessary, recalling the patient to the City of Hope for clinical evaluation, blood draw and bone marrow biopsy